Philautus glandulosus, (JERDON, 1853)

Biju, S. D. & Bossuyt, Franky, 2009, Systematics and phylogeny of Philautus Gistel, 1848 (Anura, Rhacophoridae) in the Western Ghats of India, with descriptions of 12 new species, Zoological Journal of the Linnean Society 155 (2), pp. 374-444 : 414-415

PHILAUTUS GLANDULOSUS ( JERDON, 1853)

( FIGS 2 , 5 , 19 , 31C , 34 , 35 ; TABLE 2)

Type material: Neotype, BMNH 1947.2 .27.22 (ex BMNH 1882.2.10.39), an adult male, SVL 22.3 mm, from ‘ Manantavadi’ (‘Manantodddy’) (i.e. Mananthavady), Wayanad , Kerala ( Bossuyt & Dubois, 2001).

Other material studied: BNHS 4453, an adult male, from Mercara; SDB 40239, an adult male, from Mananthavady; BNHS 4454, an adult male, from Sulthanbathery ( Table 2).

Identity: Bossuyt & Dubois (2001: 14–15) provided a detailed review on the nomenclatural history, and considered Ixalus pulcher Boulenger (1882) and Rhacophorus pulcherrimus Ahl, 1927 as synonyms of Ixalus glandulosus Günther, 1876 . In the original description, Jerdon (1853: 533) stated the snout–vent length as roughly 30.5 mm, and described the unique yellowish colour on the side and limbs ( Fig. 34 ), which exactly matches with the yellow forelimbs and lateral region of the syntype of I. pulcher , which presently is the neotype of I. glandulosus . Jerdon attributed the species epithet presumably because of its prominently granular (‘glandular’) yellow lateral side.

Diagnosis: Philautus glandulosus can be distinguished from known congeners by the following combination of characters: (1) medium male adult size (SVL 25.2 ± 2.0 mm, N = 4); (2) snout pointed; (3) head length shorter than width, HW 10.0 ± 0.6 mm, HL 9.2 ± 0.9 mm, N = 4; (4) dorsum shagreened; (5) lateral abdominal area prominently glandular; (6) fingertips rounded; (7) dorsal surface of forearm and loreal region yellow; (8) anterior and posterior surface of thighs yellow.

Philautus glandulosus is the sole Western Ghats species in the genus with an invariable yellow dorsal surface of forearm and loreal region in life, and creamy white or yellowish in preservation ( Figs 31C , 34 , 35 ). It is closely related to P. bobingeri and P. jayarami sp. nov., which it resembles well in overall appearance ( Fig. 5 ). For differences with P. bobingeri and P. jayarami sp. nov., see ‘comparison’ of those species.

Description of the neotype: A detailed description of the neotype was published in Bossuyt & Dubois (2001). Measurements are given in Table 2.

Colour in life: BNHS 4453 (in the wild), dorsum uniform dark green with a few scattered light-brown spots, lateral side yellow, loreal and tympanic regions yellow, iris reddish brown encircled by a thin bluish outer ring, forelimb yellow with a few dark-grey spots, thigh with a green line extending from dorsum to knee, anterior and posterior margins yellow, without markings, tibia almost completely green, tarsus yellow with a few scattered dark-greyish green spots; ventral side light yellow, throat, hands, and feet light yellow ( Fig. 31C ). In captivity (either in collection bags or in terrarium), this frog has the ability to change the dorsal green colour to dark purple or violet; however, the pattern is reliably constant. SDB 40239 (in captivity), dorsum uniformly dark purple, without markings, lateral side yellow, loreal and tympanic regions yellow, forelimb yellow, thigh with a purple line extending from dorsum to knee, anterior and posterior margins yellow, without markings, tibia almost completely purple, tarsus yellow; ventral side yellowish, throat, hands, and feet yellow ( Fig. 35 ).

Variation: Measurements of four specimens including neotype are given in Table 2.

Distribution and natural history: Mananthavady and Sulthanbathery of Kerala, and Mercara in Karnataka ( Fig. 31C , Table 1). This species strongly prefers vegetation layers above 4 m in height. In Wayanad this species was located either from the rainforest canopy (about 10-m high in Mananthavady) or in forest fringes near coffee plantations (about 4-m high in Sulthanbathery). In Mercara it was observed in an isolated tree in a garden at heights above 4 m. Specimens were located by their calls, and were collected during rainy evenings after 20:00 h.

Figures

Figure 2. Maximum-likelihood phylogram (GTR + G + I; –Ln L = 14 763.97) for the mitochondrial DNA data set of 1488 bp of 34 taxa of Western Ghats Philautus and five outgroup species. Numbers above branches indicate nonparametric bootstrap values under maximum parsimony (MP). Numbers below branches indicate Bayesian posterior probabilities. *Values of less than 50.

Figure 5. Morphometric distinction between males of four green Philautus species: Z, Philautus akroparallagi sp. nov.; -, Philautus bobingeri; O, Philautus glandulosus; and •, Philautus jayarami sp. nov. The ratio of the snout length (SL)/eye length (EL) is plotted against the snout–vent length SVL (see Table 2).

Figure 19. Schematic comparison of green-coloured Philautus from the Western Ghats. A, dorsal view, showing coloration of forelimbs and hindlimbs; B, lateral view of head, showing coloration of loreal/tympanic regions and forelimb; C, ventral view of snout, showing shape; D, webbing on feet. The arrows indicate extension of webbing at the fourth toe. Illustrations from left to right are: Philautus akroparallagi sp. nov., Philautus beddomii, Philautus bobingeri, Philautus chalazodes, Philautus chromasynchysi sp. nov., Philautus glandulosus, and Philautus jayarami sp. nov.

Figure 31. Distribution map. A, Philautus dubois; B, map showing Malabar (shaded in grey), from which the type of Philautus flaviventris was collected; C, Philautus glandulosus; D, Philautus graminirupes.

Figure 34. Neotype of Ixalus glandulosus (BMNH 1947.2.27.22) from ‘Manantavadi’ (i.e. Mananthavady).

Figure 35. Philautus glandulosus: a specimen from Mananthavady (SDB 40239).